Diversionary Device

ABSTRACT

In a multi-burst diversionary device (10) containing a number of pyrotechnic cartridges (22) arranged in a series and a firing arrangement (14), a first of the cartridges is ignited by the firing arrangement, the remaining cartridges are each ignited sequentially by the flash of pressure and heat (hot gasses) produced when a previous cartridge in the series deflagrates. The device has a housing (12) defining a number of compartments (20) in which the cartridges are received. The housing defines flow paths interconnecting the compartments in series and the first compartment with the firing arrangement. Each compartment is also fluidly connected with atmosphere.

CROSS-REFERENCES TO RELATED APPLICATIONS

This is a U.S. National Stage filing made pursuant to 35 U.S.C. § 371.This U.S. application claims the benefit of a prior Patent CooperationTreaty filing that was assigned Application No. PCT/GB2016/051756. Theearliest priority date in the parent application is Jun. 16, 2015

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

MICROFICHE APPENDIX

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a multi-burst diversionary device andto a method of igniting the fuzes of a plurality of pyrotechniccartridges in a multi-burst diversionary device.

2. Description of the Related Art

Diversionary devices, sometimes also referred to as stun grenades ordistraction devices, are generally intended for use by law enforcementand military personnel to physiologically and psychologically stun anintended victim or victims in high-risk situations. Known diversionarydevices generally comprise a housing containing an energetic pyrotechniccharge and a firing arrangement with a small time delay. When activated,the known diversionary devices emit a loud noise, a pressure wave and aflash of light to stun the intended victim but without expelling matterthat might cause physical injury. More recently, diversionary deviceshave been developed which emit multiple bursts of noise, pressure andlight rather than a single burst. It is believed that this is moredisorientating; especially if the bursts become louder and more intensegiving the impression the device is getting closer to the victim.

It is known to use a pyrotechnic charge housed in a replaceablecartridge in a diversionary device. The known cartridges are similar tothe so called “flash-bang” cartridges that are commercially availableand used typically for scaring birds and often comprise a cylindricalhousing containing a combustible fuze and a pyrotechnic charge. Thelength and composition of the fuze determines the time delay betweenignition of the fuze and deflagration of the pyrotechnic charge. Suchcartridges are sometime referred to as “sound units.”

In WO 2011086388 A1 the present inventor disclosed a multi-burstdiversionary device housing a number of replaceable pyrotechniccartridges. The device has a firing arrangement incorporating apercussive ignition cap containing a primer charge. When the cap isfired, a proportion of the heat and pressure given off is directed ontothe fuze of each of the cartridges so that the fuzes of all thecartridges are ignited at the same time. To provide a multi-bursteffect, the cartridges have fuzes with a different time delay arrangedso that the pyrotechnic charges are deflagrated sequentially. Whilstthis arrangement is highly effective, there are drawbacks. Generallyspeaking, in order to obtain a longer delay it is necessary to increasethe physical length of the fuze resulting in a corresponding decrease inthe volume of pyrotechnic charge that can be included in a cartridge ofany given size. As a result, there is a limit on the number cartridgesthat can be incorporated in a device before the length of fuze requiredto provide a suitable delay for the later bursts means that there isinsufficient room for an effective amount of the pyrotechnic charge. Afurther drawback is that each of the cartridges in the device must havea different delay to produce sequential firing. This requires that arange of cartridges with different fuze delays be provided and that eachdevice must be loaded with a correct set of cartridges.

It is an object of the present invention to provide a multi-burstdiversionary device which overcomes or at least mitigates the drawbacksof the known diversionary devices.

It is a further object of the invention to provide a multi-burstdiversionary device which is simpler in design and so cheaper and easierto manufacture than known multi-burst diversionary devices.

It is also an object of the invention to provide an alternative methodof igniting the fuzes of a plurality of cartridges in a multi-burstdiversionary device.

BRIEF SUMMARY OF THE PRESENT INVENTION

In accordance with a first aspect of the invention, there is provided adiversionary device comprising a housing holding a plurality ofpyrotechnic cartridges arranged in series, each cartridge having acombustible fuze and a pyrotechnic charge; and a firing arrangementincluding a primer charge; the housing defining a first flow pathconfigured to channel hot gases from the primer charge onto the fuze ofa first cartridge in the series only, the housing defining further flowpaths configured to channel a portion of the hot gasses given off ondeflagration of the pyrotechnic charge in each of the cartridges ontothe fuze of an adjacent downstream cartridge.

In a device in accordance with the first aspect of the invention, onlythe fuze of a cartridge in the first compartment in the series isignited by the printer charge, the fuzes in subsequent cartridges areignited sequentially utilizing a portion of the hot gases produced whenthe pyrotechnic charge of a cartridge in the preceding compartmentdeflagrates. Sequentially igniting successive cartridges in series givesrise to a multi-burst effect without the need for the cartridges to havefuzes with different time delays and so enables a multi-burst device tobe constructed to hold any desired number cartridges. Indeed, all thecartridges may have a fuze with the same time delay and the device couldbe loaded with a plurality of identical cartridges. This significantlysimplifies the manufacture and supply of cartridges and the loading ofthe device. That said, it will be appreciated that the cartridges neednot all be the same. For example, it may be desirable to use cartridgeswith different pyrotechnic compositions to create a particular effectover the series of bursts.

The further flow paths might be configured to channel a portion of thehot gasses given off on deflagration of the pyrotechnic charge in atleast one of the cartridges onto the fuze of at least two adjacentdownstream cartridges.

The device may hold more than one series of cartridges, the housingdefining a first flow path configured to channel hot gases from theprimer charge onto the fuze of the first cartridge in each series, thehousing defining further flow paths configured to channel a portion ofthe hot gasses given off on deflagration of the pyrotechnic charge ineach of the cartridges in each series onto the fuze of an adjacentdownstream cartridge in the series.

Each cartridge may be held in a compartment defined in the housing.

Each compartment may have a fuze end and a charge end, the further flowpaths being configured to fluidly connect a fuze end of each compartmentwith the charge end of the preceding upstream compartment in the series.

Each compartment may comprise a chamber defined within the housing, thefurther flow paths connecting the chambers sequentially in series, afuze end region of each chamber in the series downstream from the firstchamber being connected by means of a flow path with a charge end regionof the preceding upstream chamber in the series. The chambers may eachhave a substantially cylindrical region in which at least part of arespective cartridge is a close sliding fit.

The housing may also define flow paths for connecting each chamber withatmosphere. For each pair of adjacent chambers in the series, thehousing may define a flow path which interconnects the charge end regionof the upstream chamber in the pair to the fuze end region of thedownstream chamber in the pair and which also connects both end regionsto atmosphere.

The primer charge may be provided in percussion cap, the first flow pathconnecting the percussion cap with the fuze end of the first compartmentin the series. The device may further comprise a firing mechanism forselectively activating the percussion cap. The firing mechanism maycomprise a firing pin which is resiliency biased to a firing position inwhich it contacts the cap to activate the primer charge, the pin beingmovable from the firing position to a non-firing position in which it isspaced from the primer charge against the bias force. The firingmechanism may also comprise a release lever, the lever being movablebetween a non-release position in which it holds the firing pin in thenon-firing position and a released position in which the firing pin isable to move to the firing position under the bias force. The firingmechanism may also comprise a removable safety pin for holding the leverin the non-release position. The firing pin may be provided on a strikerplate.

At least some of the compartments in the series may be arranged in anarray, longitudinally overlapping one another. The compartments could bedisposed about a central axis generally parallel to one another. Thehousing may comprise a main body portion having a central axis with atleast some of the compartments disposed in the main body portion aboutthe axis. The main body portion may be generally cylindrical. Thecompartments may be arranged so that the charge end of each compartmentis located adjacent the fuze end of the next downstream chamber in theseries. The housing may comprise a first end cap and a second end cap,the end caps being releasably mountable to opposite ends of the mainbody portion, the end caps defining the further flow pathsinterconnecting compartments sequentially in series. The first end capmay also comprise a mounting for receiving a firing mechanism and defineat least part of the first flow path for fluidly connecting the primercharge with a fuze end of a first one of the compartments in the series.The compartments may be arranged in two or more rows about a centralaxis.

The compartments in the series may be arranged axially in-line. In thiscase, the housing may be elongate having an upstream end and adownstream end, the firing arrangement being located at the upstreamend. The housing may comprise a plurality of housing sections releasablymountable to one another. The housing may comprise at least two tabularhousing members including a first tubular housing member having an endcap at an upstream end incorporating, or to which is mounted, the firingmechanism and a final tubular housing member having a second end cap ata downstream end; each pair of adjacent tubular housing members beingreleasably interconnected by an adaptor. The first end closure and eachof the adaptors may define at a downstream end a recess which opens intothe interior of the adjacent downstream tubular housing member, therecess being dimensioned to receive and hold a fuze end of respectiveone of the pyrotechnic cartridges. Each of the adaptors may also definea further recess at an upstream end which opens into the interior of theadjacent upstream tubular housing member for receiving a charge end of arespective one of the pyrotechnical cartridges, the adaptor alsodefining a flow path fluidly connecting the recess at the downstream endwith the further recess at the upstream end. The adaptor flow path maycomprise at least one flow passage which is offset from the axialcentreline of the recess. The tubular housing members may each have oneor more vent openings therethrough. In accordance with a second aspectof the invention, there is provided a multi-burst diversionary devicecomprising: a housing holding a plurality of pyrotechnic cartridges anda firing arrangement operatively connected with a first one of thecartridges to ignite said first one of the cartridges only, the devicecomprising formations for directing on to each of the remainingcartridges a portion of the hot gas given off on deflagration another ofthe cartridges.

In accordance with a third aspect of the invention, there is provided amethod of operating a multi-burst diversionary device comprising aplurality of pyrotechnic cartridges each cartridge having a combustiblefuze and a pyrotechnic charge, the method comprising: a. using a primercharge to ignite the fuze of a first one of the cartridges; b.sequentially igniting the fuzes of the remaining pyrotechnic cartridgesin series by directing a portion of the hot gasses given off by anupstream cartridge in the series when it deflagrates onto the fuze ofthe next adjacent downstream cartridge.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view of a first part of the main body of adiversionary device in accordance with a first embodiment of theinvention;

FIG. 2 is similar to FIG. 1 but includes arrows indicating the directionflow of fluid along the various fluid passageways;

FIG. 3 is a longitudinal cross sectional view on an enlarged scalethrough a typical pyrotechnic cartridge for use in a diversionary devicein accordance with the invention;

FIG. 4 is a side view of a main body member forming part of a housing ofa diversionary device in accordance with a second embodiment of theinvention;

FIG. 5 is an end view of the main body member of FIG. 4;

FIG. 6 is a cross sectional view taken on line A-A of FIG. 7 of a firstend cap forming part of the housing of the diversionary device inaccordance with the second embodiment of the invention for use with themain body member of FIGS. 4 and 5;

FIG. 7 is an end view of the first end cap of FIG. 6;

FIG. 8 is a side view showing hidden detail of second end cap formingpart of the housing of the diversionary device in accordance with thesecond embodiment of the invention for use with the main body member ofFIGS. 4 and 5 and the first end cap of FIGS. 6 and 7;

FIG. 9 is an end view of the second end cap of FIG. 8;

FIG. 10 is a schematic side view of the diversionary device inaccordance with the second embodiment;

FIG. 11 is a longitudinal cross-sectional view through a diversionarydevice in accordance with a third embodiment of the invention;

FIG. 12 is a side view of an adaptor forming part of the device of FIG.11;

FIG. 13 is an end view of the adaptor of FIG. 12;

FIG. 14 is a side view of a diversionary similar to that shown in FIG.11 but expanded to include three pyrotechnic cartridges, with certainparts shown ghosted to enable internal details to be seen;

FIG. 15 is schematic representation of an alternative configuration ofpyrotechnic cartridges which could be adopted in diversionary devicesimilar to that of the first embodiment of the invention as illustratedin FIGS. 1 and 2; and,

FIG. 16 is a view similar to that of FIG. 10 illustrating an alternativearrangement of pyrotechnic cartridges in a diversionary device similarto that of the second embodiment of the invention as illustrated inFIGS. 4 to 10.

REFERENCE NUMERALS USED IN THE DRAWINGS

-   10 diversionary device-   12 body member-   12 b end cap-   12 c end cap-   14 firing mechanism-   16 mating face-   18 recess-   20 chamber-   22 pyrotechnic cartridge-   24 housing-   26 end closure-   28 pyrotechnic charge-   30 fuze-   32 extended region-   40 fluid passageway-   42 fluid passageway-   44 fluid passageway-   46 further flow passageway-   48 Y shaped passageway-   50 outlet-   52 arrow-   54 arrow-   56 passageway-   60 arrow-   68 arrow-   70 through bore-   72 end face-   74 end face-   76 spigot-   78 end face-   80 external thread-   82 central bore-   82 a internal thread-   83 percussion cap-   84 end face-   85 firing mechanism-   85 a release lever-   85 b safety pin-   86 end face-   88 central bore-   88 a recessed region-   90 bore-   92 recess-   94 bore-   96 recess-   98 recess-   100 vent hole-   102 vent hole-   104 recess-   106 recess-   108 recess-   110 vent hole-   112 row-   114 row-   115 divider-   116 flow path-   118 flow path-   120 vent hole-   122 main body section-   124 threaded spigot-   126 threaded spigot-   128 recess-   132 main body portion-   134 threaded spigot-   136 recess-   138 recess-   140 bore-   142 main body section-   144 threaded spigot-   145 recess

DETAILED DESCRIPTION OF THE INVENTION

Several embodiments of a diversionary device in accordance with thepresent invention will now be described, by way of non-limiting exampleonly, with reference to the accompanying drawings.

With reference to FIGS. 1 to 3, a diversionary device in accordance witha first embodiment of the present invention is indicated generally at10. The device 10 has a housing with a main body to which is mounted afiring mechanism, indicated schematically at 14. The main body is formedin two parts, only one of which 12 is illustrated, the other part beingsubstantially a mirror image of the part 12 shown. The part 12 is agenerally rectangular block of material having a mating face 16. Thepart 12 can be made of any suitable material such as a metallic materialincluding steel or aluminum/aluminum alloy. Formed within the materialare recesses 18 which one open on to the mating face 16. The second parthas a corresponding mating face and corresponding recesses. The twoparts 12 are connected together mating face to mating face to form themain body and held together by a number of releasable fastenings, suchas screws (not shown). When connected together, the opposed recesses 18in the mating faces 16 of the two parts define a number of cylindricalchambers 20 a-20 h arranged in a common plane, and a number of fluidpassageways which interconnect the chambers fluidly in series andconnect each of the chambers with atmosphere at the exterior of the mainbody 12. The recesses also define a first fluid passageway which fluidlyconnects only a first of the chambers with the firing arrangement.

In the present embodiment, there are eight chambers in the main body butthe number of chambers can be varied as desired. Each of the chambers 20has a cylindrical region configured to receive a cylindrical pyrotechniccartridge 22, an example of which is shown in FIG. 3 on an enlargedscale.

Each cartridge 22 has a cylindrical housing 24 closed at one end by anend closure 26. The housing contains a pyrotechnic charge 28 locatedtowards the closed end of the housing and an ignitable and combustiblefuze 30 at the open end. Each chamber 20 has a fuze end 20′ and a chargeend 20″, the cartridges 22 being inserted in the chambers with the openfuze at the fuze end 20′ of each chamber as illustrated schematically inchambers 20 a to 20 c in FIG. 1 with the cross hatching representing thefuze 30. At the charge end, the chambers have an extended region 32 ofreduced diameter in comparison with the cylindrical region into whichthe end closure 26 of the cartridge is blown when the pyrotechnic chargeis ignited and deflagrates.

The cartridges 22 may be similar to so called “flash-bang” cartridgesthat are commercially available and used typically for scaring birds.The cylindrical housing 24 may be made of paper or cardboard or the likebut any suitable material can be used. The pyrotechnic charge 28 may beany suitable composition which produces the required combination ofsound, light and pressure. A differently composed pyrotechnic charge 28may be used in some/all of the cartridges 22 in the device 10 to createdifferent effects. For example, the cartridges 26 may have differentpyrotechnic charge compositions so that when ignited sequentially, eachsuccessive cartridge produces a louder noise, more light and morepressure. This gives the impression that the device 10 is moving closerto the victim even though the device is substantially stationary.

Whilst it is expected that the device in accordance with the inventionwill use pyrotechnic cartridges with a combustible fuze 30 to provide adelay between each successive deflagration (“flash-bang”), at least somepyrotechnic cartridges with no fuze could be used, though this wouldresult in a series of closely spaced bangs.

Seven of the chambers 20 b-20 h are arranged parallel to one another ina closely spaced array whilst the first chamber 20 a is inclined at anangle to the others and is more widely spaced at its fuze end 20′. Thispositions the fuze end 20′ of the first chamber 20 a so as to be moreeasily connected with the firing arrangement 14 by a first fluidpassageway 40. The firing arrangement is releasably mountable to themain body 12 and houses a percussive ignition cap containing a primercharge which emits a flash of heat and pressure (hot gasses) when thecap is struck with a sufficient force. The firing arrangement alsoincludes a firing mechanism to fire the ignition cap. This can be anysuitable arrangement such as a conventional spring loaded striker plateand release leaver assembly of the type described in WO 2011086388 A1.However, any suitable firing mechanism could be used such as an inertiaactivated toggle of the type disclosed in EP 1705454 B. For convenience,the term “flash” will be used in this description to refer collectivelyto the heat, pressure wave, light, sound and material given off by theprimer charge in the percussion cap when it is set off and/or by apyrotechnic charge in one of the cartridges 22 when it deflagrates. Itwill be understood, however, that it is the hot gas or gases given offor produced by the pyrotechnic charges which is of primary importancefor use in igniting a fuze 30 of a subsequent cartridge 22.

The firing arrangement includes a fluid passageway which connects withthe first fluid passageway 40 in the main body to form a flow path alongwhich at least a portion of the hot gasses given off by the primercharge is able to flow into the fuze end 20′ of the first chamber 20 a.Fluid passageways 42, 44 defined in the main body connect the fuze endand the charge end respectively of the first chamber 20 a to atmosphereat the exterior of the main body. A further flow passageway 46 fluidlyconnects the charge end of the first chamber 20 a to the fuze end of thesecond chamber 20 b. The chambers are all positioned top to toe so thatthe fuze end of one chamber is located next to the charge end of theadjacent chamber or chambers. Adjacent pairs of the second to eighthchambers 20 b to 2 h are each interconnected by a generally “Y” shapedfluid passageway 48. The “Y” shaped passageway 48 interconnecting thesecond chamber 20 b and the third chamber 20 c will be described indetail. This “Y” shaped passageway 48 includes a first fluid passagewayportion 48 a extending coaxially from the fuze end of the downstreamchamber 20 c to an outlet 50 at the edge of the main body 12 where itopens into the atmosphere. A second passageway portion 48 b extends fromthe extended region 32 at the charge end of the upstream chamber 20 b tothe first passageway portion 48 a approximately midway between theoutlet 50 and the chamber 20 c. The second passageway portion 48 bextends from a position approximately midway along the extended region32 so that it is not blocked by the cartridge end closure 26 which isblown into the end of the extend region when the cartridge is fired. Thesecond passageway is angled relative to the axis of the upstream chamber20 b so that fluid flowing thought it is directed into the firstpassageway portion 48 a primarily in an outward direction towards theoutlet end 50 such that when the pyrotechnic charge in chamber 20 bdeflagrates, most of the flash given off will pass out of the main bodythrough first passageway portion outlet 50 as indicated by arrow 52 inFIG. 2. However, some of the flash, including hot gases, will flow alongthe first passageway portion 48 a into the fuze end of the downstreamchamber 20 c, as indicated by arrow 54. The remaining pairs of chambers20 c and 20 d, 2 d and 20 e, 20 e and 20 f, 20 f and 20 g, 20 g and 20 hare each interconnected by a similar “Y” shaped passage way 48 and thecharge end of the final chamber 20 h is connected to atmosphere by apassageway 56 which extends from the extended region 32 to an outlet 58at the edge of the main body.

In use, the device 10 is loaded with a cartridge 22 in each of thechambers 20, the main body is assembled and the firing arrangement withthe primer charge mounted to the main body. When the firing arrangementis activated, the primer charge gives off a flash of pressure and heatand material including hot gasses which passes through the first fluidflow passageway 40 into the fuze end of the first chamber 20 a, asindicated by arrow 60 and ignites the fuze 30 of the cartridge in thefirst chamber 20 a. After a short delay determined by the fuze 30 of thefirst cartridge, the main pyrotechnic charge 28 b is ignited anddeflagrates giving off a larger flash of light, heat, pressure wave andsound. The majority of the flash passes through the fluid passageways42, 44 to atmosphere as indicated by arrows 62 and 64 to produce a burstof sound, light and pressure. However, as indicated by arrow 66, aportion of the flash, including hot gas, passes along the fluid flowpassageway 46 to enter the fuze end of the second chamber 20 b where itignites the fuze 30 of the cartridge in the second chamber. After afurther short delay, determined by the fuze 30 in the second cartridge,the main pyrotechnic charge 28 in the second cartridge deflagrates. Thebulk of the flash given off by the second cartridge passes out of thedevice through the first and second fluid passage way portions 48 a, 48b and outlet 50 of the “Y” shaped passageway 48 interconnecting thesecond and third chambers 20 b, 20 c as indicated by arrows 52, thoughsome will pass out of the main body through the fluid passageway 46, theextended region 32 of first chamber 20 a and fluid flow passageway 44. Aproportion of the flash of heat and pressure including hot gasses givenoff by the pyrotechnic charge of the cartridge in the second chamber 10b though passes along the first passage portion 48 a into the fuze endof the third chamber 20 c, as indicated by arrow 54, where it ignitesthe fuze 30 of the cartridge in the third chamber. The process continuesin a chain-like reaction, with all the remaining cartridges 22 in thedevice being sequentially ignited from the flash given off by theprevious, upstream cartridge in the series. Connecting the cartridgestogether sequentially in series in the manner of a daisy chain enablesthe cartridges to he fired sequentially without the need to usedifferent length fuzes. This means that virtually any number ofcartridges could be included in the device without unduly limiting theamount of pyrotechnic charge that can be incorporated in thosecartridges that are fired later in the sequence and allows the device tobe loaded with a plurality of identical cartridges if desired.

FIG. 15 illustrates schematically an alternative configuration ofcartridges 22 in a planar array that could be adopted in a device 10 asdescribed above. In this configuration, the cartridges are arranged intwo rows and the arrows 68 indicate the flow of hot gases from onecartridge to next in the series in order that, with the exception of thefirst cartridge which is ignited from a primer charge, each of theremaining cartridges are ignited in turn by the hot gasses given offwhen the previous cartridge ignites. It will be appreciated than manyother configurations could be adopted by suitable design of thecartridge chambers and interconnecting flow paths.

It will be appreciated that the concept of sequentially ignitingsubsequent cartridges in a multi-burst diversionary device is notlimited to devices where the chambers are arranged in a common plane butcan be adapted for use in devices with a range of different designs,provided that fluid flow paths for directing or channeling a proportionof the flash, and in particular the hot gas, given off or generated byeach cartridge as it deflagrates onto the fuze an adjacent cartridgedownstream in the series are defined. For example, the chambers could bealigned co-axially in-line with one another or they could be arrangedabout a common axis in a cylindrical housing as described in thefollowing embodiments.

FIGS. 4 to 10 illustrate a further embodiment of a diversionary device10′ in accordance with the invention in which the housing is generallycylindrical and the compartments 20 are arranged in a circular arrayabout a central longitudinal axis.

The housing 12 of the device 10′ comprises three main parts, a maincylindrical body member 12 a, a first end cap 12 b and a second end cap12 c. Extending through the main body 12 a is a small diameter centralthrough bore 70 aligned with a central longitudinal axis of the mainbody. Disposed in and about the central through bore and longitudinalaxis is an array of 6 larger diameter through bores 20 a to 20 f whichdefine compartments or chambers for receiving pyrotechnic cartridges 22,such as those shown in FIG. 3. The compartments 20 are not equi-spacedabout the central axis but arranged into adjacent pairs.

The end caps 12 b and 12 c are releasably mounted to opposite ends ofthe main body to hold the cartridges 22 in their respective compartmentsand serve to define flow paths that connect the compartments in seriesfor sequential, serial ignition of the cartridges.

A first end cap 12 a comprises a cylindrical disc portion having anouter diameter which is substantially the same as that of the main body12 a and which has a planar end face 72 which abuts an end face 74 ofthe main body when the housing is assembled. A spigot 76 projectsaxially out from the other end face 78 of the disc. The spigot 76 has anexternal thread 80 on to which can be mounted a firing pin arrangement.A central bore 82 extends through the first end cap. An inner end region82 a of the bore has an internal thread whilst an outer end region is 82b is recessed to hold a percussive ignition cap 83 containing a primercharge.

The second end cap 12 c is also in the form a cylindrical disc having anouter diameter which is substantially the same as that of the main body12 a and which has a planar end face 84 which abuts the other end face86 of the main body when the housing is assembled. A central bore 88extends through the centre of the disc, the bore having a wider diameterrecessed region 88 a at its outer end. When the housing 12 is assembled,the end caps 12 b, 12 c are clamped firmly to the ends of the main body12 a by means of an elongate screw (not shown) which is inserted thoughthe central bore 88 in the second end cap and the central bore 70 in themain body to engage with the internal thread 82 a in the central bore ofthe first end cap. The elongate screw having a head which is received inthe recess 88 a of the central bore 88 in the second end cap.

The cartridges 22 in the compartments 20 a-20 f are arranged head totoe, with the fuzes 30 of the cartridges in the first, third, and fifthcompartment 20 a, 20 c, 20 e being located adjacent the first end cap 12b and the fuzes 30 of the cartridges in the second, fourth and sixthcompartments 20 b, 20 d, 20 f being located adjacent the second end cap.

A bore 90 extends through the disc portion of the first end cap 12 b inregistration with the fuze end of the first compartment 20 a. A radiallyextending recess 92 is provided in the inner face of the disc whichmerges with the bore 90 and extends radially inwardly. An angled bore 94connects the interior of the recess with an outer end region of thecentral through bore 82. The central through bore 82, the angled bore 94and the recess 92 together define a first flow path along which the hotgasses given off by the primer charge in the ignition cap 83 in theouter recessed end of the bore 82 can flow to enter the fuze end of thefirst compartment 20 a. The bore 90 forms an exhaust vent through whicha portion of the flash given off when the pyrotechnic charge of thecartridge in the first compartment deflagrates can escape to atmosphere.

Two arcuate recesses 96, 98 are formed in the inner face 72 of the firstend cap 12 a, each recess being connected to atmosphere by an exhaustvent hole 100 extending through the remainder of the end cap to theouter end face 78 of the disc portion. A first of the recesses 96partially overlaps the ends of the second and third compartments 20 b,20 c in the main body to define a flow path fluidly interconnecting thecharge end of the second compartment 20 b with the fuze end of the thirdcompartment 20 c. The recess 96 and the vent hole 100 also fluidlyconnect the two chambers with atmosphere. The second of the recesses 98partially overlaps the ends of the fourth and fifth compartments 20 d,20 e in the main body to define a flow path fluidly interconnecting thecharge end of the fourth compartment 20 d with the fuze end of the fifthcompartment 20 d. The recess 98 and the vent hole 100 also connect thetwo chambers 20 d, 20 e with atmosphere. A further exhaust vent hole 102is formed through the disc portion of the first end cap in line with thesixth compartment 20 f to connect the compartment with atmosphere.

Three circular recesses 104, 106, 108 are formed in the inner matingsurface 84 of the second end cap 12 c equi-spaced about its centre. Asmaller diameter exhaust vent hole 110 is formed through the remainderof the disc portion at the base of each of the recesses to connect eachrecess with atmosphere. The recesses 104, 106, 108 are positioned sothat each one aligns with a respective pair of the compartments 20 a-20f. The circular recesses 104, 106, 108 are dimensioned so that they onlypartially overlap the ends of the adjacent compartments so as to fluidlyconnect them whilst the second end cap 12 c holds the cartridges in thecompartments. The exhaust vent holes 1 10 fluidly connected the tworespective compartments to atmosphere. In this embodiment, a firstcircular recess 104 aligns with the ends of the first and secondcompartments 20 a, 20 b in the main body so as to fluidly connect thecharge end of the first compartment 20 a with the fuze end of the secondcompartment 20 b, the vent hole 110 fluidly connecting the compartments20 a, 20 b with atmosphere. A second circular of the recesses 106 alignswith the ends of the third and fourth compartments 20 c, 20 d in themain body so as to fluidly connect the charge end of the thirdcompartment 20 c with the fuze end of the fourth compartment 20 d, thevent hole 110 fluidly connecting the compartments 20 c, 20 d withatmosphere. A third of the circular recesses 108 aligns with the ends ofthe fifth and sixth compartments 20 e, 20 f in the main body so as tofluidly connect the charge end of the fifth compartment 20 e with thefuze end of the sixth compartment 20 f, the vent hole 110 fluidlyconnecting both compartments 20 e, 20 f with atmosphere.

In the assembled device 10′, the recesses and vent holes in the end caps12 b, 12 c form flow paths which connect all the compartments 20 a-20 fsequentially in series. In other words, they form a chain of flow pathswhich allow each cartridge downstream from the first to be ignited bythe hot gasses from the preceding cartridge in the series when itdeflagrates.

The fuze end of the first chamber 20 a is fluidly connected with theprimer charge in the firing arrangement via the recess 92, the angledbore 94 and the axial bore 82 in the first end cap which collectivelyform a first fluid passageway. The charge end of the first compartment20 a is connected with the fuze end of the second compartment 20 b bythe first circular recess 104 in the second end cap. The charge end ofthe second compartment 20 b is connected with the fuze end of the thirdcompartment 20 c by the first arcuate recess 96 in the first end cap.The charge end of the third compartment 20 c is connected with the fuzeend of the fourth compartment 20 d by the second circular recess 106 inthe second end cap. The charge end of the fourth compartment 20 d isconnected with the fuze end of the fifth compartment 20 e by the secondarcuate recess 98 in the first end cap. Finally, the charge end of thefilth compartment 20 e is connected with the fuze end of the sixthcompartment 20 f by the third circular recess 108 in the second end cap.

In use, a pyrotechnic cartridge 22 is loaded into each of thecompartments 20 a-20 f in the main body 12 a in the appropriateorientation. The end caps 12 b, 12 c are mounted to the ends of the mainbody and secured in position. A percussion cap 83 including a primercharge is loaded into the recessed end 82 b of the axial bore in thefirst end cap 12 b and a firing mechanism 85 is mounted to the first endcap 12 b. The firing mechanism 85 is a conventional firing mechanism ofthe type disclosed in WO 2011086388 A1 and comprises a release lever 85a for controlling the release of a spring loaded striker plate whichwhen released is urged to strike the percussion cap in order to set offthe primer charge and a removable safety pin 85 b. However, other typesof firing mechanism can be adopted. When the device 10 is activated andthe primer charge set off, the flash of heat, pressure and materialgiven off by the primer charge passes through the first fluid passagewaycomprising the axial bore 82, the angled bore 94, and the recess 92 inthe first end cap and enters the fuze end of the first compartment 20 ato ignite the fuze 30 of the cartridge in the first compartment. After ashort delay, the pyrotechnic charge 28 in the first cartridge is ignitedand deflagrates giving off a large flash of light, heat, pressure wave,and sound. The majority of this flash passes out through the vent hole90 and the vent hole 110 in the first circular recess 104. However, aportion of the flash including hot gas is guided by the first circularrecess to enter the fuze end of the second compartment 20 b where itignites the fuze of the second cartridge in the second compartment 20 b.When the second cartridge deflagrates, the majority of the flash givenoff passes out though the vent hole 110 in the first circular recess 104and the vent hole 100 in the first arcuate recess 96 in the first endcap 12 b. A portion of the hot gasses though is guided by the firstarcuate recess 96 to enter the fuze end of the third compartment 20 c toignite the fuze of the third cartridge in the third compartment. Thisprocess continues with each cartridge being ignited by a portion of thehot gasses (flash) given off by the cartridge in the previous upstreamcompartment by means of the flow paths as described above. FIG. 10 is asomewhat schematic side view of the assembled device 10′ which isghosted to show the positions of the cartridges 22 in main body member12 a, though details of the compartments 20 a-20 f themselves areomitted for clarity. Arrows 54 indicate the flow of hot gas from onecartridge when it deflagrates onto the fuze of the next adjacentdownstream cartridge to ignite the fuze of the downstream cartridge. Thearrows 52 indicate the movement of flash to atmosphere through theexhaust vent holes when each cartridge deflagrates.

It will be appreciated various changes can be made to the device 10′without departing from the inventive concept. For example the number ofcompartments in the main body 12 a can be changed with an appropriatechange to design of the end caps 12 b, 12 c to ensure that thecompartments are connected in series. Other changes can also be made.For example, elongate actuate holes could be provided through the discpart of the first end cap 12 b rather than the recesses 96, 98 and ventholes 100. Similarly, the circular recesses 104, 106, 108 in the secondend cap 12 c could be replaced by simple through holes. These changeswould allow the compartments to vent more easily ensuring that asufficiently large flash is emitted whilst the shroud effect of the endcap surrounding the holes constrains sufficient heat and pressure (hotgas) given off by one cartridge when it deflagrates to pass though tothe fuze end of the next compartment. The disc portion may need to be ofsufficient thickness to ensure that it channels sufficient of the hotgasses onto the fuze of the downstream cartridge but this can beestablished for each application relatively easily by means of trial anderror if necessary. With the benefit of the teaching in this patentspecification, those skilled in the art will have no difficulty inconfiguring the housing so as to deflect part of the hot gasses givenoff by each cartridge onto the fuze of an adjacent downstream cartridge.

FIG. 16 illustrates a modified version of the device 10′a in which thecartridges are arranged in two rows 112, 114 stacked one above the other(as shown) in modified main body portion 12 a′ and separated by adivider 115. The main body portion defines flow paths 116, 118 whichdirect hot gases between pyrotechnic cartridges 22 vertically adjacentone another in the two rows so that all the cartridges can be ignitedsequentially in series. The flow paths are arranged so that a firstcartridge 22 a in the row 112 adjacent the first end cap 12 b is ignitedfrom the primer charge. A proportion of the flash given off when thefirst cartridge 22 a deflagrates is directed by means of flow passage116 on to the fuze of a second cartridge 22 b immediately below thefirst cartridge in the row 114 adjacent the second end cap 12 b. Flashfrom the second cartridge 22 b is directed by a suitable flow pathdefined in the second end cap 12 c on to the fuze of a third cartridgein the same row 114, whilst flow passage 118 directs a proportion of theflash from the third cartridge 22 c on to the fuze of a fourth cartridge22 d in the first row 112 immediately above the third cartridge. Similararrangements interconnect all the remaining pyrotechnic cartridges 22 inthe device. It will be appreciated that various different configurationsof cartridges can be adopted by suitable design of the chambers andinterconnecting flow paths.

FIGS. 11 to 14 illustrate a still further embodiment of a diversionarydevice 10″ in accordance with the invention. In the device 10″ accordingto this embodiment, the compartments and cartridges are aligned axiallyin-line with one another. In the embodiment as shown in FIG. 12, thereare two compartments 20 a, 20 b each housing a corresponding cartridge22 a, 22 b. However, the device is modular in nature and any number ofadditional compartments/cartridges can be added and FIG. 14 illustratesthe device 10″ having three compartments 20 a, 20 b, 20 c.

The device 10″ comprises a housing 12 including a first end cap 12 b atan upstream end of the device and a second end cap 12 c at a downstreamend. At least two tubular housing members 12 d, 12 e, 12 f are arrangedbetween the first and second end caps with adjacent tubular housingmembers being interconnected by an adaptor 12 g. The components of thehousing can be made of any suitable materials such as metallic materialsincluding steel or aluminum/aluminum alloy.

The tubular housing members 12 d, 12 e, 12 f are identical andinterchangeable. They each have an internal thread at either end forconnection with an end cap 12 b, 12 c or adaptor 12 g and a number ofexhaust vent holes 120.

The first end cap 12 b is located at the upstream end of the device 10″.It includes a main body section 122 with a first threaded spigot 124which projects from the inner end of the main body section forengagement with the thread at one end of a first tubular housing member12 d to secure them together. A second threaded spigot 126 projects fromthe outer end of the main body section 122. The second spigot 126 issmaller in diameter than the first and has an external thread on towhich can be mounted a firing mechanism 85 similar to that of theprevious embodiment, as is shown in FIG. 14. A circular recess 128 isformed coaxially in the inner end of the first threaded spigot. Therecess 128 is dimensioned to receive and hold the fuze end of apyrotechnic cartridge 22 a. The recess may have tapered side walls forease of inserting the cartridge. An axial bore 82 extends through thesecond spigot 126 and opens into the recess 128. The bore has a steppedlarger diameter portion 82 a at its outer end in which a percussion cap83 containing a primer charge can be mounted. The firing mechanism 85includes a striker plate and/or a firing pin which is urged to strikethe percussion cap 83 when the device 10″ is activated so as to producea flash of heat and pressure (hot gasses) and material which travelsdown the axial bore 82 to ignite the fee of the first cartridge 22 a.The axial bore 82 in this embodiment comprises a first flow path whilstthe downstream recess 128 in the first end cap 12 b and thecorresponding tubular housing member 12 d together define the firstcompartment 20 a for receiving the first pyrotechnic cartridge 22 a.

Each adaptor 12 g has a main body portion 132 with a threaded spigot 134projecting from either end. The spigots 134 are similar to the firstspigot 124 on the first end cap 12 b and are configured to engage withthe threads at the ends of two adjacent tabular housing members 12 d &12 e or 12 e & 12 f to join them together. A circular and tapered recess136 is formed at the downstream end of each adaptor for holding the fuzeend of a cartridge 22 b, 22 c in a manner similar to the recess 128 inthe first end cap 12 b. A further circular recess 138 is formed in theupstream end of each adaptor to hold the charge end of the upstreamcartridge 22 a, 22 b. The two recesses are fluidly connected by means offour bores 140 equi-spaced about a longitudinal axis of the device. Thedownstream recess 136 in the adaptor and the adjacent downstream tubularhousing member 12 e, 12 fd together define a compartment 20 b, 20 c forreceiving the respective pyrotechnic cartridge 22 b, 22 c. Thedownstream end of the last tubular housing member, 12 e, 12 f is closedby the second end cap 12 c. The second end cap 12 c comprises a mainbody section 142 with a threaded spigot 144 projecting from the upstreamend of the main body section for engagement with the thread at the endof the last tubular housing member 12 e, 12 f. A circular recess 145 isformed in the upstream end of the second end cap to hold the charge endof the upstream cartridge 22 b, 22 c.

When the device is activated, a flash of heat and pressure and materialproduced when the primer charge in the percussion cap 83 is set offtravels down the axial bore 82 in the first end cap 12 b and ignites thefuze of the first cartridge 22 a. After a delay determined by the fuze,the first cartridge deflagrates giving off a larger flash of heat,pressure wave, sound and light. The bulk of this flash passes outthrough the vent holes 120 in the first tubular housing member but aportion of the hot gas in particular passes through the recess 138 inthe upstream end of the adaptor and the four bores 140 to ignite thefuze of the second cartridge 22 b. After a further delay, thepyrotechnic charge in the second cartridge deflagrates giving of a flashof heat, pressure, sound and light, most of which passes out through thevent holes 120 in the second tubular housing member 12 e. Where thedevice 10″ has more than two cartridges, the process continues with eachcartridge in the chain being ignited by the deflagration of the chargein the preceding upstream cartridge. In FIG. 14, the arrows 52schematically illustrate the flow paths of the flash passing out throughthe vent holes from each cartridge as it deflagrates and the arrows 54indicate the flow path for hot gasses from one chamber to the next tocause sequential firing of the cartridges. It will be appreciated thatthe carriages are set off sequentially and not simultaneously.

It has been found that it is advantageous to offset the flow paththrough the adaptor 12 g from the central axis of the cartridges hencethe use of the offset bores 140. However, it will be appreciated thatthe design of the flow path could be varied in a number of ways and isnot limited the arrangements shown.

The main body portions 122, 132, 142 of the end caps and the adaptorhave a hexagonal outer profile so that the device 10″ will tend to cometo a rest more quickly on a surface when thrown as compared with adevice which is wholly cylindrical. Nevertheless, this feature is notessential to the main inventive concept.

If more “bangs” are required, the device 10″ can be extended by using anadditional adaptor 12 g and tubular housing member 12 d, 12 e, 2 f foreach additional cartridge. In each device 10″ the first end cap 12 b ismounted at the upstream end of the first tubular housing member and thesecond end cap 12 c mounted to the downstream end of the last tubularhousing member, with each adjacent pair of tubular housing members beinginterconnected by an adaptor 12 g.

The above embodiments are described by way of example only. Manyvariations are possible without departing from the scope of theinvention as defined in the appended claims. For example, generally itis expected that a diversionary device in accordance with the invention,all the pyrotechnic cartridges will be interconnected in a single seriesso as to be ignited sequentially. However, the cartridges could bearranged in more than one series, with a first cartridge in each seriesbeing ignited from a primer charge and the remaining cartridges in eachseries being ignited by the hot gas given off when the previouscartridge in the series deflagrates. In a further alterative, thecartridges may be arranged in a series which splits into two or morepaths. For example, two cartridges might both be ignited from the hotgas given off by a single previous cartridge in a series. Thisarrangement could be used to produce a loud bang at the end of a seriesby setting off two cartridges at the same time.

Having described my invention, I claim:
 1. A diversionary devicecomprising: a housing holding a plurality pyrotechnic cartridgesarranged in series, each cartridge having a combustible fuze and apyrotechnic charge; a firing arrangement including a primer charge; andthe housing defining a first flow path configured to channel hot gasses(flash) given off by the primer charge onto the fuze of a firstcartridge in the series only, the housing defining further flow pathsconfigured to channel a portion of the hot gas (flash) produced ondeflagration of the pyrotechnic charge in each of the cartridgesupstream from a last cartridge in the series onto the fuze of anadjacent downstream cartridge.
 2. A diversionary device as claimed inclaim 1, wherein the housing defines a plurality of compartments, eachcompartment for holding a respective one of the pyrotechnic cartridges.3. A diversionary device as claimed in claim 2, wherein each compartmenthas a fuze end and a charge end, each cartridge being located in itsrespective compartment with its fuze at the fuze end of the compartmentand the further flow paths being configured to connect a fuze end ofeach compartment with the charge end of the preceding upstreamcompartment in the series.
 4. A diversionary device as claimed in claim3, wherein each compartment comprises a chamber defined within thehousing, the further flow paths connecting the chambers sequentially inseries, a fuze end region of each chamber in the series downstream fromthe first chamber being connected by means of a flow path with a chargeend region of the preceding upstream chamber in the series.
 5. Adiversionary device as claimed in claim 1, wherein, for each pair ofadjacent chambers in the series, the housing defines a flow path whichinterconnects the charge end region of the upstream chamber in the pairto the fuze end region of the downstream chamber in the pair and whichalso connects both end regions to atmosphere.
 6. A diversionary deviceas claimed in claim 3, wherein the housing comprises a main body portionhaving a central axis with compartments disposed in the main bodyportion about the axis, the compartments arranged so that the charge endof each compartment is located adjacent the fuze end of the nextdownstream chamber in the series; the housing also comprising a firstend cap and a second end cap, the end caps being releasably mountable toopposite ends of the main body portion, the end caps defining thefurther flow paths interconnecting compartments sequentially in series.7. A diversionary device as claimed in claim 6, wherein the first endcap comprises a mounting for receiving a firing mechanism and defines atleast part of the first flow path for fluidly connecting the primercharge with a fuze end of a first one of the compartments in the series.8. A diversionary device as claimed in claim 1, wherein the compartmentsare disposed generally in a common plane.
 9. A diversionary device asclaimed in claim, wherein the housing comprises a main body in which thecompartments are located and a firing mechanism releasably mountable tothe main body, the main body having two parts releasably attachable toone another, the chambers and fluid flow paths being defined bycorresponding formations in mating faces of the two parts.
 10. Adiversionary device as claimed in claim 1, wherein the compartments arearranged axially in-line.
 11. A diversionary device as claimed in claim10, wherein the housing is elongate having an upstream end and adownstream end, the firing arrangement being located at the upstreamend.
 12. A diversionary device as claimed in claim 11, wherein thehousing comprises at least two tubular housing members including a firsttubular housing member having an end cap at an upstream endincorporating or to which is mounted the firing mechanism and a finaltubular housing member having a second end cap at a downstream end; eachpair of adjacent tubular housing members being releasably interconnectedby an adaptor.
 13. A diversionary device as claimed in claim 12, whereinthe first end cap and each of the adaptors define at a downstream end arecess which opens into the interior the adjacent downstream tubularhousing member, the recess being dimensioned to receive a fuze end of arespective one of the pyrotechnic cartridges.
 14. A diversionary deviceas claimed in claim 13, wherein each adaptor defines at an upstream enda further recess which opens into the interior of the adjacent upstreamtubular housing member for receiving a charge end of a respective one ofthe pyrotechnic cartridges; each adaptor farther defining a flow pathfluidly connecting the recess at the downstream end and the furtherrecess at the upstream end.
 15. A diversionary device as claimed inclaim 14, wherein the adaptor flow path comprises at least one flowpassage which is offset from the axial centreline of the recess.
 16. Amulti-burst diversionary device comprising: a housing holding aplurality of pyrotechnic cartridges and a firing arrangement operativelyconnected with a first one of the cartridges to ignite said first one ofthe cartridges only, the device comprising formations for directing onto each of the remaining cartridges a portion of the hot gas given offon deflagration another of the cartridges.
 17. A method of operating amulti-burst diversionary device comprising a plurality of pyrotechniccartridges each cartridge having a combustible fuze and a pyrotechniccharge, the method comprising: (a) using a primer charge to ignite thefuze of a first one of the cartridges; and (b) sequentially igniting thefuzes of the remaining pyrotechnic cartridges in series by directing aportion of the hot gas produced when each cartridge deflagrates onto thefuze of another of the cartridges.